The 1964 Fender Stratocaster represents a historical pivot, a decisive moment in music: it marks the day Dylan went electric. By 1965, the folk musician had largely established himself as the folksy, acoustic voice of a generation. So when he took the stage at that year’s Newport Folk Festival toting a guitar that — gasp! — required plugging in, the instrument became an instant point of contention and an instant historical icon.

So where is the guitar-that-changed history today? It depends who you ask. A New Jersey woman, daughter of a pilot who flew Dylan’s 1960s-era chartered tour planes, says she’s had the instrument for decades. One of Dylan’s lawyers, however, disagrees, claiming that the singer still has the instrument in his care, the Associated Press reports.

Dawn Peterson said her father, pilot Victor Quinto, took the guitar home after Dylan left it on a plane. He kept it, she said, after failed attempts to contact the musician’s representatives to come pick it up. After Quinto died, Peterson kept the guitar, unaware of its significance until a friend saw it and encouraged her to investigate. About a year ago, she contacted PBS’s “History Detectives,” who were at first skeptical that Dylan would have left behind such an important instrument. But the clues seemed to add up: handwritten song lyrics, for example, were found tucked in the case — and experts identified the penmanship as Dylan’s. Andy Babiuk, an instrument appraiser and guitar expert, said he was “99.9 percent certain” that Dylan played the Stratocaster in question at Newport.

But while some historians have said the story checks out, the singer’s lawyer, Orin Snyder, remained firm in his dissent. “[Dylan] did own several other Stratocaster guitars that were stolen from him around that time, as were some handwritten lyrics,” Snyder said in a statement. “In addition, Bob recalls driving to the Newport Folk Festival, along with two of his friends, not flying.”

Experts estimate that if the 1964 Stratocaster were to go on sale — the authentic one, of course — it could fetch as much as half a million dollars. Peterson said she has no plans to sell or donate it. “History Detectives” stands by its appraisal, and would “welcome the opportunity” to inspect the guitar Dylan believes to be authentic, a PBS spokesperson said. The episode featuring the investigation airs on PBS Tuesday, July 17th, at 9 p.m. EST.